Weft storage motion and measuring device for weaving machines

ABSTRACT

The invention pertains to a weft storage motion and pick measuring device for weaving machines for taking off weft periodically from stationary supply packages with at least one loop former positioned between a supply package and point of weft insertion and acting substantially at right angles to the travel of weft yarn (in that section) and actuatable in synchronism with the weft insertion itself.

United States Patent" Inventor Erich Walter Hortmann Schotten, Germany 7Appl. No. 793,521

Filed Jan. 23, 1969 Patented Feb. 9, 1971 Assignee Georg Fischer Ltd.Brugg Brugg, Switzerland Priority Feb. 16, 1968 Switzerland 2288/68 WEFTSTORAGE MOTION AND MEASURING DEVICE FOR WEAVING MACHINES 8 Claims, 8Drawing Figs.

US. Cl 139/122 Int. Cl D0311 47/34 Field of Search 139/12 2- ReferencesCited UNITEDSTATES PATENTS 2,589,429 3/1952 Pfarrwaller 139/1223,425,462 2/1969 Pfarrwaller 139/122 FOREIGN PATENTS 1,336,177 7/1963France 139/122 Primary Examiner-Henry S. .Iaudon Attorney-Rodney C.Southworth ABSTRACT: The invention pertains to a weft storage motion andpick measuring device for weaving machines for taking off weftperiodically from stationary supply packages with at least one loopformer positioned between a supply package and point of weft insertionand acting substantially at right angles to the travel of weft yarn (inthat section) and actuatable in synchronism with the weft insertionitself.

v PATENIEDFEB 1911 3.561.499

SHEET 2 BF 3 I /j// ///////l INVENTUR.

Erich Walter Horlmann WEFT STORAGE MOTION AND MEASURING DEVICE FORWEAVING MACHINES BACKGROUND OF THE INVENTION In many, so-called,shuttleless-type weaving machines adapted to operate at high speeds itmay be very advantageous to provide means to premeasure and store aquantity of weft prior to insertion thereof. This can diminish greatlystrain on the weft and thus permit higher speeds, especially forrelatively weak yarns.

To store the weft to be inserted, motions of a similar type, such as,e.g., that described in the Austrian Pat. No. 223,144, are provided withtwo movable and one fixed thread eyelet between the stationary supplypackageand the point of weft insertion, whereby a length of yarn isprepared when the movable eyelet swings out, said length of yarn thenbeing used for the weft insertion on the subsequent swinging back ofboth movable eyelets.

Other motions are known which are provided with a plurality of weft yarnguides, see Swiss Pat. No. 407,904, controlled in groups, whereby eachof these weft yarn guides is provided with at least one thread eyeletthrough which the weft is always passed.

The disadvantage of all these yarn guides is that when swinging out theycreate a considerable deviation in the pathway of the passing yarn inthe range of their thread eyelets, whereby a larger stored length ofyarn requires a longer stroke of the thread guide or a higher number ofthread guides. Forone solution it was therefore proposed to have oneeach of such groups of yarn guides work only on every second pick, thusmaking it possible to work with a lower yarn speed. The higher thenumber of deviation points fonned by the thread eyelets the greater thetravel and consequently the greater the strain on the weft yarn at agiven yarn speed, particularly during the taking-ofl of stored weft bythe weft insertion mechanism.

Another weft storage motion and measuring device for a weaving machineis shown in Swiss Pat. No. 409,816 in which the required length of weftis measured by'a transport roller and then fed to a suction channel inwhich, by means of reduced pressure, a yarn loop is formed which isperiodically caught by the weft insertion member. This system, however,

requires an extra means for the inducing the vacuumalf the suctionchannel is a round tube the yarn loop can twist upon itself and form asnarl and thereby create difficulties in that the snarl does notuntangle when the weft is pulled out of the tube.

Full use of a weft storage motion on a weaving machine can only be madeif the weft storage motion treats the yarn as gently as possible anddoes in no way limit the production of the weaving machine.

It is a purpose of the invention to produce a device which avoids thedisadvantages of the known designs and which ensures a gentle treatmentof the weft yarn during drawing from the supply package, during storingand subsequent insertion into the shed.

It is also desirable to provide storage to function intermittently aswith multicolor weaving.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic view ofaweaving machine with a weft storage motion as per the invention in afirst configuration, as seen from the cloth side of the machine,

FIG. 2 is a view from the top onto the storage motion as per theinvention and FIG. I, fitted on the right hand side of the weavingmachine,

FIG. 3 shows a section along the line lI-ll in FIG. 2,

FIG. 4 shows in section at Ill-III, FIG. 3, elements of the device,

FIG. 5 shows a schematic view of movement according to a first form ofthe invention,

FIG. 5a shows a detail of the loop formation,

FIG. 6 shows a graph of the storage-of one length of the yarn inrelation to one revolution of the control shaft in the configuration asper FIG. 5, and

FIG. 7 shows the arrangement of another configuration for the storageand for the withdrawal of weft already delivered.

DESCRIPTION OF THE PREFERRED EMBODIMENT An example of an arrangement ofthe device as per the invention applied to a rapier loom with flexibletapes with weft carriers is shown in FIG. 1, with a loom frameconsisting of loom sides I, 2 and girts 3, 4. The loom is driven by amotor 5 with brake and clutch via gearwheels. Parts 6 and 7 are housingscontaining drive means (not shown) for the flexible tapes 6a and 7a withweft carriers (not shown) serving the weft in sertion members. A housing9 contains the elements (not shown) necessary for the weft control,including a weft depressor, weft positioner, clamp, cutter and holder.10 are harness frames and II is a housing for clock springs for pullingback the harness frames against the action of their cams. Details ofsuch a weaving machine are to be found in US. Pat. No. 2,641,285.

Supply packages 13 and 14 are mounted on an arm 12. The yarn 15 is drawnoff these supply packages 13 and 14, respectively, and stored in astorage motion generally marked 16 from where it is transferred by theelements of the weft control motion 9 to the weft carries and is therebyinserted into the shed of a fabric being woven.

FIG. 2 shows the storage motion 16 as seen from the top with an intakebrake 17. The supply packages 13 and I4 are SUMMARY OF THE INVENTION Thedevice as per the invention is characterized by the fact that one ormore eyeletless loop formers having a smooth effective surface arearranged pivotably to extend through corresponding slots of a wallconsisting of smooth, ribbed sections to hold or serve one each of theweft loops and their respective weft loop arms.

These loop formers are cam controlled to swing upwardly in their slotsto draw weft from a supply and are then returned to their inactiveposition. This movement of the loop formers is controlled in synchronismwith the weft insertion and progressively thereby to draw weft with aminimum of drag and with the least possible strain on it.

The drawings show two examples of the subject of invention.

arranged before the intake brake 17 whereby yarn is drawn off only onepackagewhilst the other one is provided as a reserve. A weft clamp ispart of the weft control motion 9 and is arranged near the yarn outletof the storage motion I6. A shaft 19 provides the rotating connectionfrom the loom drive to the storage motion 16. This drive may beconnected through to any convenient, rotating part of the weavingmachine so long as the storage device makes one cycle for every pickinserted. A handle 20 allows manual operation of the storage motion 16via elements (not shown) for instance, when a new weft is threaded in.

The knob 21 serves to lift up the hood 32 which is borne on studs or ona shaft 34, FIG. 3. v

FIG. 3 shows a section along the line II-II of FIG. 2. A shaft 23fomiing a mutual pivot for a plurality of adjacently arranged loopformers 24a, 24b, 24c, 24d, etc. is borne in a housing 22. In unactuatedor idle position each one of the loop formers 24 is held in a lowerstarting position shown in full lines by means of a spring 25, one foreach arm, said starting position being determined by a stop 26 inhousing 22. Each loop former 24 carries a roller 27 on a short arm,which is aligned for effective engagement with a cam 28. A cam 28 isallocated to each loop former 24 and the cams 28 are fastened adjacentto each other on a mutual rotating shaft 29 which is borne in a housing22 and driven by the driving shaft 19.

The loop formers 24 project with their one end 30 out of a wall 31a ofthe housing 22, said wall 31a being formed by or as cambered flat ribs,whereby the center of the camber of the wall 31a is approximatelyidentical with the center of the shaft 23. The equally cambered hood 32is concentrically with or parallel to the cambered wall 31a in such away that between hood 32 and wall 31a there is a cambered space 23(FIGS. 3 and 4). One each thread eyelet 35a and 35b, respectively, arearranged at both ends of the housing (FIGS. 3 and 5), whereby a threadpassing through both eyelets 35a and 35b runs over the smooth uppersurfaces of the ends 30 of the loop formers 24 when they are in theirlower position.

FIG. 4 shows part of the section along the line III-III in FIG. 3through the wall 31a, whereby 32 represents the cor responding part orrib of the hood 32. Wall 31a and hood 32 thus ribbed, define slots 40perpendicular to the shaft 23 and in which one each of the loop formers24 can move with its end 30.

The outside of the wall 31a being divided into flat ribs 31 is alsoprovided with recesses 36 to take the yarn loops 37 formed by loop arms37a and 37b with an upper radius 370. The sidewalls of the raised edges36a of the recesses 36 limit the slots 40.

FIG. 5 shows schematically how the yarn loops 37 are formed, whereby theloop formers 24a and 2411 have already completed the loops 37 with theirends 30a and 30b, whilst the loop former 24c with its end 30c is in thecourse of forming a loop. As soon as the end 300 has reached its endposition or shortly before, the end 30d of the loop former 241d willstart its stroke. The flat ribs 31 are provided with thread holdbacknoses 38a pointing toward the hood and matching the thread holdbacknoses 38b which are provided on the hood 32. During the loop-formingprocess these thread holdback noses guide the thread 15 in such a waythat the base of each loop 37 remains approximately on the original pathof the thread 15 in the direction of arrow 43 (FIG. 5).

FIG. 5a shows the upper radius 370 of a yarn loop. The ends of the loopformers are preferrably hardened and are very smoothly polished.

FIG. 6 is a graph showing how the storage of a yarn length progresses inrelation to one revolution of the shaft 29, (FIG. 3). It is, e.g.,assumed that the required yarn length 44 for one pick is 240 cm. ofwhich approximately three-fourths corresponding with 180 cm. are to bestored, whilst the remaining 60 cm. are to be pulled off the supplypackage 14 directly by the weft insertion member. It is also assumedthat during 180 no yarn is required for the weft insertion and that thestoring process can still continue when the weft insertion member startspulling out yarn for the insertion of the pick. The full line shows howthe yarn length to be pulled off the supply package 14 increases,depending on the rotating angle of the shaft 29, while the dotted lineshows the yarn requirement without weft storage motion. From this itbecomes obvious that the weft storage motion 16 as per the inventionallows a substantially constant and thus ideal pulling-off of yarn fromthe supply package. The ideal line is shown in the dot-anddash line.

The following is a brief description of the function starting with allloop formers 24 (FIG. 3) being at rest position (down) and the shaft 29at 0 (FIG. 6). The thread 15 passes from the supply package 14 throughthe intake brake 17, thereafter through the thread eyelet 35a, then overall ends 30 of the loop formers 24, however, below the thread holdbacknoses 38a and 38b, then through a further thread eyelet 35b to the weftcontrol clamp 18, which is closed, and then to the actual weft controlmotion where the thread 15 is held waiting to be pulled down and caughtby the insertion member. The shaft 29 which is rotating at the samespeed or in a ratio of even numbers with the main shaft of the weavingmachine, rotates in the direction of the arrow (FIG. 3), whereby thefirst control cam 28 via roller 27 starts to move the loop former 24aand thus lifts the thread 15, Le, the forming of a first loop begins.

The control cams 28 which are arranged parallel to each other aremounted on the shaft 29 staggered to one another in such a way thatwhenever a loop former 24 has nearly reached its'top end position, thenext loop former 24 starts to move. The yarn necessary to form the loop37 is drawn from the supply package 14. This process is repeated as manytimes as there are control cams 28 and loop formers 24 provided; ac-

cording to FIG. 5, there are e.g., five pairs and in the graph as perFIG. 6, e.g., nine pairs of loop formers.

The control cams 28 are shaped in such a way that when the loop former24 has reached its top end position the roller 27 follows a dwell 28a(concentric section) of the cam 28 until at least two more loop formers24 have reached their end position. Subsequently the roller 27 isreleased by a drop 28!) of the cam 28 in such a way that the loop former24, under the influence of spring 25, returns to its basic position. Theloop 37 formed prior to the return of loop former 24 remains intactbecause the end 30 of the loop former 24 is not provided with any threadeyelet. The cambered form of the ribs 31 and notches 36 ensures that themeasured loop 37- does not fall back into any undesiredposition by theinfluence of gravity or change its position otherwise.

On FIG. 6 it can be seen that at about the time, with reference to theangle of rotation of the shaft 29, when the last loop fonner 24 reachesits top position. shown in dotted lines in FIG. 3, the insertion memberhas caught the thread 15 and thereby requires yarn for the weftinsertion. The weft clamp 18 has been opened prior to this moment sothat the required yarn can be taken from the first loop 37 from the weftstorage motion 16, FIG. 2.

When the first loop is used up, the yarn is taken ofi from the secondloop without there being any resistance against its being drawn by thecarrier. Before the last loop is required the corresponding last loopformer has returned to its rest position so that the taking thereofmeets no resistance. As soon as the last yarn loop is used up, thedrawing of further yarn must come directly from the supply package 14,whereby the weft insertion member is already operating in the phase ofdecelerating speed, which for the pulling-off of yarn is about the sameas that for the preceding storage process. From this there thus resultsa substantially constant drawing off speed of the yarn from the supplypackage 14 which is obviously the ideal condition. At the position of360 the insertion member has completed its work, the weft clamp isclosed and the storing process starts all over again.

FIG. 7 shows an arrangement of the loop formers 24 with ends 30 for analternate form of the invention in which the storing motion 16 has alsothe task of withdrawing a certain length of yarn which was alreadydelivered, as it is required for some known systems of weaving machines(such as e.g. that of Swiss Pat. No. 407,904). For this purpose afurther weft clamp 39 is required which can also be actuated by acontrol cam (not shown) mounted on the shaft 29.

This weft clamp 39 is closed when the insertion member has reached itsend position whereupon the loop former 24: puts in a loop, the yarn forwhich is drawn back through the weft clamp 18. During this process theweft clamp 18 remains, of course, open and closes only when the loopfonner 24z has reached its top, end position. Only-now does the'firstloop former 24a begin its storingmovement as earlier described.

Certain lively yarns involve the risk that after withdrawal of the loopformers 24, that is, at the moment when the loops 37 lie freely in thenotches 36 of the flat ribs 31, the loop arms 37a and 37b of the loops37 tend to twist partly as at or ad jacent their radius sections 37c oreven for their whole length, about each other. This undesired twistingof loops can influence the perfect yarn feed from the storage into thefabric shed. In order to avoid this, the distance, i.e., the camberedspace 33 between the raised edges 36a of the notches 36 in the flat ribs31 and the inner surface of the cambered hood 32 in which the yarn ismoved to form the loop, is set bigger than the thickness of the yarn,however, smaller than the radius 37c of the loops 37 being formed whenputting in the yarn.

It is within the scope of the invention to provide an arrangement offour weft storage motions and measuring devices as it can e.g., be usedfor weaving four different types of weft yarn. The four supply packagesand the four allocated weft storage motions and measuring devicesoperate with a weft clamp and a set of yarn guiding fingers which, in amanner (not'shown) can be actuated by a card control motion or otherpattern means, but which are not the subject matter of the present invention.

The invention can be used for the exact measuring of pick lengths.Although for mere storage functions this is not required it is obviousthat by altering the stroke of the control cams 28a, precise measuringof any specified loop length is possible.

As compared with known weft storage motions the design as per theinvention has the advantage that when drawing out the loops theyam doesnot have to pass any hindering or retarding eyelets at the loop formers.It can thus be achieved that the drawing off of yarn from the supplypackage can take place at nearly constant speed during the storingprocess as wellas during the taking off directly from the supply packageimmediately after having drawn all the loops 37 from the storage motion.

This disclosure of a preferred embodiment and modification of theinvention is to be interpreted as illustrative of forms the inventionmay take and modifications thereon will readily occur to those skilledin the art. The invention is not to be restricted except by the scope ofthe appended claims wherein the novel features desired to be protectedby Letters Patent are set forth:

lclaim:

l. A weft storage motion and measuring device for weaving machines fordrawing ofi' weft periodically from stationary supply packages with atleast one loop former being positioned between a supply package andpoint of weft insertion and functioning substantially at right angles tothe path of the weft yarn and operable synchronously with the weftinsertion, characterized in that, at least one eyeletless loop fon'ner(24) having an end with a smooth effective surface for yarn support issupported pivotally to move in an arc in a confining slot (40) of a wall(31a) consisting of flat riblike sections (31), said sections having aconfiguration such that they hold one weft loop arm (37a, 37b)respectively, of a weft loop.

2. A weft storage motion and measuring device as defined in claim 1,wherein the flat, riblike sections (31) of the wall (31a) are camberedlengthwise.

3. A weft storage motion and measuring device as defined in claim I.wherein the riblike sections (31) are provided with means defining looprestraining notches (36) the raised edges (36a) of which define withtheir sides. slots (40) in which the loop formers (24) are moved.

4. A weft storage motion and measuring device as defined in claim 1,wherein a cambered hood (32) is provided and has ribs which form betweenthem slots (40a) serving to cover the riblike sections (31) in the wall(31a), and means on which said hood is hinged for lifting.

' 5. A weft storage and measuring device as defined in claim 4,characterized in that a cambered space (33) between the raised edges(36a) of the notches (36) in the sections (31) and the inner surface ofthe cambered hood (32) is bigger than the thickness of the yarn when thehood (32) is closed, but smaller than the radius (37c) of the loop (37)formed during the st0ring process.

6. A weft storage motion and storage device as defined in claim 1,characterized in that the loop formers (24) are pivotable around a shaft(23) bourne in a storage motion housing (22), the center of shaft (23)being positioned approximately at the center of curvature of thecambered wall (31a) with the sections (31 7. A weft storage motion andmeasuring device as defined in claim 6, characterized in that the loopformers (24) are actuated in one direction of movement by control cams(28) via rollers (27) and in the opposite direction by springs (25 8. Aweft storage motion and measuring device as defined in claim 6,characterizedin that the control earns (28) for the drive of the loopformers (24) are arranged on ashaft (29) rotating in the ratio l l or inanother ratio of even numbers with a main driving shaft of the loom.

1. A weft storage motion and measuring device for weaving machines fordrawing off weft periodically from stationary supply packages with atleast one loop former being positioned between a supply package andpoint of weft insertion and functioning substantially at right angles tothe path of the weft yarn and operable synchronously with the weftinsertion, characterized in that, at least one eyeletless loop former(24) having an end with a smooth effective surface for yarn support issupported pivotally to move in an arc in a confining slot (40) of a wall(31a) consisting of flat riblike sections (31), said sections having aconfiguration such that they hold one weft loop arm (37a, 37b)respectively, of a weft loop.
 2. A weft storage motion and measuringdevice as defined in claim 1, wherein the flat, riblike sections (31) ofthe wall (31a) are cambered lengthwise.
 3. A weft storage motion andmeasuring device as defined in claim 1, wherein the riblike sections(31) are provided with means defining loop rEstraining notches (36) theraised edges (36a) of which define with their sides, slots (40) in whichthe loop formers (24) are moved.
 4. A weft storage motion and measuringdevice as defined in claim 1, wherein a cambered hood (32) is providedand has ribs which form between them slots (40a) serving to cover theriblike sections (31) in the wall (31a), and means on which said hood ishinged for lifting.
 5. A weft storage and measuring device as defined inclaim 4, characterized in that a cambered space (33) between the raisededges (36a) of the notches (36) in the sections (31) and the innersurface of the cambered hood (32) is bigger than the thickness of theyarn when the hood (32) is closed, but smaller than the radius (37c) ofthe loop (37) formed during the storing process.
 6. A weft storagemotion and storage device as defined in claim 1, characterized in thatthe loop formers (24) are pivotable around a shaft (23) bourne in astorage motion housing (22), the center of shaft (23) being positionedapproximately at the center of curvature of the cambered wall (31a) withthe sections (31).
 7. A weft storage motion and measuring device asdefined in claim 6, characterized in that the loop formers (24) areactuated in one direction of movement by control cams (28) via rollers(27) and in the opposite direction by springs (25).
 8. A weft storagemotion and measuring device as defined in claim 6, characterized in thatthe control cams (28) for the drive of the loop formers (24) arearranged on a shaft (29) rotating in the ratio 1 : 1 or in another ratioof even numbers with a main driving shaft of the loom.